In recent years, the flip-chip mounting of ICs has been rapidly becoming widespread with views to thinner and smaller circuit boards with the pervasion of portable information terminals. In addition, in SAW (Surface Acoustic Wave) devices used for mobile phones, the flip-chip mounting is also beginning to rapidly prevail.
However, for the flip-chip mounting technique, unlike the conventional mounting technique, various connection methods are available and the present situation is that companies in the art are employing various methods, while groping thereabout, in terms of intellectual property rights, reliability, and the like. Among these methods, there has been a rapid increase in cases where heating and pressurizing are involved in the process of post-bonding with adhesive, ACF, or the like from the aforementioned point of view. An example of such a conventional heating and pressurizing method is described below with reference to the accompanying drawings.
FIG. 9 is an explanatory view of the flip-chip mounting process using the conventional heating and pressurizing method. In FIG. 9, reference numeral 1 denotes a nozzle for holding an electronic component 8 by suction, numeral 4 denotes a heating part for curing a bonding element 9, and numeral 6 denotes a table part on which a circuit board 7 is to be placed. In such a constitution, the bonding element 9 is previously applied to a mounting portion on the circuit board 7 where the electronic component 8 is to be mounted, and the circuit board 7 with the bonding element 9 is fixed onto the table part 6. Then, the table part 6 moves, so that the mounting portion is placed just under the nozzle 1. After that, the nozzle 1 moves down so that the electronic component 8 is mounted to the mounting portion via the bonding element 9. Then, while the electronic component 8 is pressurized against the circuit board 7 by the nozzle 1, the bonding element 9 is cured by heat generation of the heating part 4.
With the flip-chip mounting by using a heating and pressurizing technique of the conventional method as described above, it takes about 7 seconds for the circuit board 7 in which the bonding element 9 has previously been applied to the electronic-component mounting portion to be carried into the flip-chip mounter. The electronic components 8 are then mounted in about 7 seconds per electronic component, and about 60 seconds are required for the heating and pressurizing time for curing the bonding element 9 in the mounting process. Afterwards, the next circuit board 7 takes 7 seconds to be carried into the mounter successively, and a similar production operation is iterated. Therefore, when one electronic component 8 is flip-chip-mounted onto one circuit board 7, the production cycle time for each circuit board 7 is about 74 seconds.
However, in the above conventional process, although electronic components can be flip-chip-mounted onto the circuit board with high precision and high speed in the flip-chip mounter, the production rate comes to an abrupt fall because the heating and pressurizing operation for curing the bonding element 9 is also executed in the flip-chip mounter, prolonging the time required for the whole mounting process.